[INFO] cloning repository https://github.com/abuit/rust-markov
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/abuit/rust-markov" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabuit%2Frust-markov", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabuit%2Frust-markov'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 95ec4e97ce1f93dc5a402b4659a30b83966e182f
[INFO] building abuit/rust-markov against master#0da281b6068a7d889ae89a9bd8991284cc9b7535 for pr-103610
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fabuit%2Frust-markov" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/abuit/rust-markov on toolchain 0da281b6068a7d889ae89a9bd8991284cc9b7535
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0da281b6068a7d889ae89a9bd8991284cc9b7535" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/abuit/rust-markov
[INFO] finished tweaking git repo https://github.com/abuit/rust-markov
[INFO] tweaked toml for git repo https://github.com/abuit/rust-markov written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/abuit/rust-markov already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0da281b6068a7d889ae89a9bd8991284cc9b7535" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:83125433e4fff17b1ac56874832f668d9df75ee638575aca552b68e127bedee9" "/opt/rustwide/cargo-home/bin/cargo" "+0da281b6068a7d889ae89a9bd8991284cc9b7535" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 145506a9f9dd151b24dfcb0b21418f296f57ea88a9afc270e12d9fadd2fa01a9
[INFO] running `Command { std: "docker" "start" "-a" "145506a9f9dd151b24dfcb0b21418f296f57ea88a9afc270e12d9fadd2fa01a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "145506a9f9dd151b24dfcb0b21418f296f57ea88a9afc270e12d9fadd2fa01a9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "145506a9f9dd151b24dfcb0b21418f296f57ea88a9afc270e12d9fadd2fa01a9", kill_on_drop: false }`
[INFO] [stdout] 145506a9f9dd151b24dfcb0b21418f296f57ea88a9afc270e12d9fadd2fa01a9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:83125433e4fff17b1ac56874832f668d9df75ee638575aca552b68e127bedee9" "/opt/rustwide/cargo-home/bin/cargo" "+0da281b6068a7d889ae89a9bd8991284cc9b7535" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 05a5ecb8e1d55895af3931d1a08516bf9f326ec5691552c361aaa8eb25295d17
[INFO] running `Command { std: "docker" "start" "-a" "05a5ecb8e1d55895af3931d1a08516bf9f326ec5691552c361aaa8eb25295d17", kill_on_drop: false }`
[INFO] [stderr]    Compiling rand_core v0.4.0
[INFO] [stderr]    Compiling autocfg v0.1.4
[INFO] [stderr]    Compiling libc v0.2.55
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]    Compiling rand_hc v0.1.0
[INFO] [stderr]    Compiling rand_isaac v0.1.1
[INFO] [stderr]    Compiling rand_xorshift v0.1.1
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling rust-markov v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/main.rs:62:21
[INFO] [stdout]    |
[INFO] [stdout] 62 |                     &preceding_word_vec.1.push((&text[word_start..counter], 1));
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 62 |                     let _ = &preceding_word_vec.1.push((&text[word_start..counter], 1));
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.51s
[INFO] running `Command { std: "docker" "inspect" "05a5ecb8e1d55895af3931d1a08516bf9f326ec5691552c361aaa8eb25295d17", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "05a5ecb8e1d55895af3931d1a08516bf9f326ec5691552c361aaa8eb25295d17", kill_on_drop: false }`
[INFO] [stdout] 05a5ecb8e1d55895af3931d1a08516bf9f326ec5691552c361aaa8eb25295d17
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:83125433e4fff17b1ac56874832f668d9df75ee638575aca552b68e127bedee9" "/opt/rustwide/cargo-home/bin/cargo" "+0da281b6068a7d889ae89a9bd8991284cc9b7535" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 59ad380e33154a4b4eb17efbdeae2c64a1bee2a7aba9a0b11f92ceb6d5fbb96e
[INFO] running `Command { std: "docker" "start" "-a" "59ad380e33154a4b4eb17efbdeae2c64a1bee2a7aba9a0b11f92ceb6d5fbb96e", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust-markov v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/main.rs:62:21
[INFO] [stdout]    |
[INFO] [stdout] 62 |                     &preceding_word_vec.1.push((&text[word_start..counter], 1));
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 62 |                     let _ = &preceding_word_vec.1.push((&text[word_start..counter], 1));
[INFO] [stdout]    |                     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.56s
[INFO] running `Command { std: "docker" "inspect" "59ad380e33154a4b4eb17efbdeae2c64a1bee2a7aba9a0b11f92ceb6d5fbb96e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59ad380e33154a4b4eb17efbdeae2c64a1bee2a7aba9a0b11f92ceb6d5fbb96e", kill_on_drop: false }`
[INFO] [stdout] 59ad380e33154a4b4eb17efbdeae2c64a1bee2a7aba9a0b11f92ceb6d5fbb96e